Frequency of Squamous Cell Esophageal Cancer among Afghan Men and local Pashtoons - Role of Social Class diet and Other Risk Factors

ORIGINAL ARTICLE Frequency of Squamous Cell Esophageal Cancer among Afghan Men and local Pashtoons - Role of Social Class diet and Other Risk Factors SHERBAT KHAN, SHAHID RAZA KALID, MOHAMMAD SALEEM* ABSTRACT Hospital-based case-control study datum were used to analyze the disparity and relation between social classes for Afghan men and local Pashtoons of Quetta and surroundings All the four major risk factors like low income, moderate/heavy Hot Tea intake, tobacco use, and infrequent consumption of raw fruits and vegetables contributed for almost all of the squamous cell esophageal cancers in Local Pashtoon in Quetta (98%) and Afghans (99%) and for 99% of the excess Frequency among Afghan men. The poverty was a major risk factor Therefore, lifestyle changes, especially a lowered intake of Hot Tea i.e., beverages, would markedly decrease the Frequency of squamous cell esophageal cancer in both Social groups and would decrease the Social disparity in risk. Further studies are required which may help to identify a new set of exposures of OSCC that are preventable and changeable. Key words: Hot tea; diet; esophageal neoplasm; risk factors; social class; tobacco, poverty. INTRODUCTION OSCC is relatively common in east Asia including Japan than other European nations1. OSCC is the most common histological type world wide and the sixth most common cause of cancer related death 2, and is a treatment resistant cancer that can with stand a combination of surgery, radio therapy, chemo therapy and other modes of treatment. Thus it is valuable to identify risk factors and also to detect high risks groups for primary and secondary prevention. We conducted a Hospitalbased case-control study of OSCC among Local Pashtoon in Quetta and Afghan men coming to Quetta for treatment and that frequent consumption of raw fruits and vegetables contributed to the low risk 3. In this paper, we analyze the relation and disparity between social class factors and OSCC and the extent to which Hot Tea, tobacco, diet, and low income causes higher Frequency among Afghan men than among Local Pashtoon in Quetta. MATERIALS AND METHODS Squamous cell esophageal cancer and Risk factors like Hot Tea, tobacco, diet, and low income which may cause higher Frequency of OSCC among Afghan men than among Local Pashtoon in Quetta. A total of 300 male cases (100 Local Pashtoon in Quetta, 200 Afghan) and 1,300 male controls (700 Local Pashtoon in Quetta, 600 Afghan) were ----------------------------------------------------------------------- Department of Gastroenterology & Surgery*, Bolan Medical College Quetta Correspondence to Dr. Sherbat Khan, Assistant Professor. Cell 03458168187 analysed from seven geographic areas (Quetta,Pishin, Zhob, Killa Abdullah, Lorali, Ziarat and Sibi). Cases were residents of the above said areas aged 30 79 years who had been diagnosed with histologically confirmed esophageal cancer between 2001 and 2011. The odds s for subjects with annual incomes less than RS10,000 versus incomes of Rs. 25,000 or more were 4.3 ( confidence : 2.1, 8.7) for Local Pashtoon in Quetta and 8.0 [Afghan men] ( : 4.3, 15.0) The Afghans belonged to southern Afghanistan. The majority approached Quetta for treatment belonged to poor social class. Case-control studies of four cancers (cancers of the esophagus, prostate, pancreas and multiple myeloma) were carried out in five geographic areas of the Quetta during2001 2010., One large control group was selected for all four types of cancer for efficiency. All Afghan men and Local Pashtoons in Quetta male residents of Quetta, Pishin, Zhob, Killa abdullah, and Lorali aged 30 79 years who had been diagnosed with histologically confirmed esophageal cancer between August 1, 2001 and April 30, 2010 for esophageal cancer component were eligible for study. Controls were selected for similarity with the age, locality, gender, and area distribution of the four types of cancer combined. Controls aged 30 64 years were selected using a random digit dialing technique 4 whereas controls aged 65 80 years were randomly chosen from computerized registn of hospital Personal in- interviews of 15 minutes were carried out with the patient and control group, usually in Hospital. Prior to interview informed consent for the study was taken from each person, on 224 P J M H S VOL.6 NO.1 JAN MAR 2012

Frequency of Squamous Cell Esophageal Cancer among Afghan Men and local Pashtoons sociodemographic factors detailed information was obtained, like use of tobacco and Hot Tea, usual adult diet, usual occupation, medical and dental history, and family history of cancer. Interviews were completed for 68 percent of both Local Pashtoon in Quetta cases and Afghan cases. The response rates were 72 percent and 76 percent, respectively, for the Local Pashtoon in Quetta and Afghan controls. For the random controls, the response rates were 75 percent and 76 percent, respectively, for Local Pashtoon in Quetta and Afghans in the interview phase. The main reasons for non inclusion were death (18 percent of cases, 1 percent of controls refusal (4 percent of cases, 15 percent of controls illness (8 percent of cases, 3percent of controls), Evaluations were based on 300 cases (100 Local Pashtoon in Quetta, 200 Afghan) and 1,300 controls (700 Local Pashtoon in Quetta, 600 Afghan). Twenty-six cases (5 Local Pashtoon in Quetta, 21 Afghan) under 65 years of age were not included in the evaluation because of not having a telephone, a criteria for the selection of control. RESULTS Table 1 shows numbers of patients, controls and or by sociodemographic indicators related to risk and by locality. Compared with Local Pashtoon in Quetta, Afghans, less educated, less dental visits, were having no technical or administrative job and as a helper and laborer had a lower socioeconomic status.were poor, were widowed or divorced and were more below the poverty line more likely to have been born in the Southern Afghanistan. Adjustment for Hot Tea use (in 10 categories, the highest being 120 Hot Tea per week) had little impact on the risk estimates for income. risks were strongly associated with low income, reaching 4.3 (Local Pashtoon in Quetta) and 8.0 (Afghans) for subjects with annual income less than RS10,000 compared with RS25,000 or more. On relative scale evaluation of income The odds s for Local Pashtoon in Quetta associated with incomes of RS25,000 49,999, RS15,000 24,999, and <RS15,000 were 1.3, 2.1, and 3.9, respectively, compared with an income of RS50,000 or more. For Afghans, the odds s associated with incomes of RS15,000 25,000, RS8,000 15.00, and <RS8,000 were 2.3, 3.0, and 8.7, respectively, compared with an income of RS25,000 or more we recalculated odds s for Afghans and Local Pashtoon in Quetta separately using approximate locality-specific quartiles as cut points. s were significantly elevated in both localities for men who rarely visited a dentist (ORs were 1.7 for Local Pashtoon in Quetta and 1.6 for Afghans) and for those with incomes at or below the poverty level (ORs were 2.6 for Local Pashtoon in Quetta and 4.2 for Afghans). Significant associations were also seen for Afghans whose marital status was widowed (odds (OR) =2.5) or never married (OR = 3.9) versus married, whose educational level was high school graduation (OR =2.8) or less (OR =3.1) versus more than a high school education, and whose usual employment was as a laborer or helper (OR=4.2) versus an administrative/technical job No significant excess risks were seen for low occupationbased socioeconomic status (ORs were 1.8 for both localities) and for place of birth in the Southern Afghanistan (ORs were 1.4 for both localities).. Risks for annual income, however, remained significantly elevated when adjusted for the other social class variables. When adjusted for annual income, all risks associated with other social class variables were reduced and not significantly elevated. Common risks association: Table 2 elaborates, the all the risks in combination with income category associated with and hot tea were consistent with independent effects on a multiplicative scale (p = 0.116) but not on an additive scale (p < 0.001). Gradients of increasing risk with decreasing income were seen for each hot tea/ naswar taking category. While increasing risks for hot tea/naswar taking were seen for each income category, the risks were highest among heavy Hot tea drinkers (>35 Hot Tea per week) with annual incomes of <RS10,000/- and the table 3 presents, large differences in risk were seen for income level within each fruit/vegetable consumption category, but there were only small differences in risk for fruit/vegetable consumption within income categories. We used income as the measure of social class in the HAR and summary HAR estimates because its dominant effect subsumed the other social class variables and it appeared to have effects independent of Hot Tea, naswar taking, and diet in our evaluation. The overall risks associated with income category combined with frequency of raw fruit and vegetable consumption were not statistically different from either a multiplicative model (p = 0.600) or an additive model (p = 0.473). P J M H S VOL.6 NO.1 JAN MAR 2012 225

Frequency of Squamous Cell Esophageal Cancer among Afghan Men and local Pashtoons Table 1: Risk of OSCC and sociodemographic factors in Local Pashtoon in Quetta and Afghans, 2001 2010 study area, age, Hot Tea use, years of Naswar / snuff taking, and raw vegetable and fruit consumption Annual income. Factors Local Pashtoon in Quetta Afghans n=100 Control (n=700) OR Cl OR Cl n=200 Control (n=600) confidence confidence Income in rupees per anum 25,000 32 389 1.0 - - - 20 171 1.0 10,000-51 241 2.0 1.1 - - 63 238 2.3 1.3, 4.3 24,999 3.6 <10,000 29 53 4.3 2.1 8.7 128 161 8.0 4.3, 15.0 Married 80 594 1.0-1.0-104 399 1.0 1.0 Widow 15 49 1.1 0.5 0.9 0.4 41 77 2.5 1.5, 4.4 1.7 0.9, 3.1 2.3 1.9 Divorced 15 61 1.0 0.5 0.6 0.3 59 112 1.6 1.0, 2.4 1.1 0.6, 1.7 2.1 1.4 Unmarried 9 39 1.5 0.6 3.8 1.1 0.4 2.7 24 23 3.9 1.8, 8.2 2.0 0.9, 4.5 Educational level >High 35 344 1.0 1.0 13 122 1.0 1.0 school High school 33 208 1.1 0.9 0.9 0.5 49 136 2.8 1.4, 5.9 2.1 0.9, 4.7 2.6 1.6 Middle 47 188 1.5 0.9 1.0 0.5 164 353 3.1 1.6, 6.1 1.8 0.9, 3.9 2.6 1.8 Dental visits Once a year 44 395 1.0 1.0 35 175 1.0 1.0 Every 1-3 13 130 0.9 0.4 0.8 0.4 28 95 1.2 0.6, 2.2 1.0 0.5, 1.9 years 1.8 1.6 Rarely 55 152 1.8 1.1 3.0 1.4 0.8 2.5 143 288 1.7 1.1, 2.8 1.4 0.8, 2.2 Occupational group Clerical/ 13 144 0.7 0.4 0.6 0.3 13 59 1.3 0.4, 4.1 0.8 0.3, 2.7 sales 1.4 1.3 Govt. job 10 37 1.8 0.7 1.3 0.5 33 72 2.5 0.9, 6.8 1.1 0.4, 3.1 4.8 3.4 Farmer 4 7 1.0 0.0 0.6 0.0 8 11 4.3 1.0, 18.0 1.3 0.3, 6.5 10.3 7.0 Driver 63 284 1.3 0.7 0.9 0.5 128 345 2.4 1.0, 5.7 1.2 0.5, 3.00 2.2 1.7 Labourer 3 14 1.7 0.4 7.6 1.2 0.3 5.1 39 49 4.2 1.6, 11.3 1.5 0.5, 4.4 Socioeconomic status Good 15 164 1.0 1.0 5 35 1.0 1.0 Poor 57 217 1.8 0.9 1.3 0.6 172 383 1.8 0.6, 5.3 0.7 0.2, 2.3 3.5 2.6 Place of birth Non southern Afghanistan 84 496 1.0 1.0 38 115 1.0 1.0 Southern Afthanistan Poverty index Above poverty thresh hold At or below poverty thresh hold 15 156 1.4 0.6 3.4 1.3 0.5 3.1 178 451 1.4 0.8, 2.3 1.2 0.7, 2.0 96 635 1.0 1.0 95 450 1.0 1.0 19 39 2.6 1.3 5.4 1.1 0.4 3.4 115 118 4.2 2.8, 6.4 1.8 0.9, 3.6 226 P J M H S VOL.6 NO.1 JAN MAR 2012

Sherbat Khan, Shahid Raza Kalid, Mohammad Saleem Table 2: OR for annual income and categories of Naswar taking/snuff and Hot Tea beverage use among Afghans and Local Pashtoon in Quetta with OSCC, 2001 2010 Naswar taking/snuff Annual income and no of hot tea per week Rs.25,000/- Rs. 10,000-Rs.24,999/- <Rs.10,000/- Light smoker Hot Tea/week 0 15 1.0 7.8 1.7, 35.7 14.1 2.9, 67.6 16 35 2.0 0.2, 23.1 14.6 2.9, 73.8 71.8 15.0, 343.9 >35 38.7 7.1, 210.4 98.8 20.9, 467.3 231.6 48.2, 1,114 Heavy smoker Hot Tea/week 0 15 4.1 0.8, 20.9 12.0 2.6, 55.0 49.2 10.9, 221.7 16 35 28.4 6.5, 124.7 46.2 10.4, 204.4 80.4 17.6, 367.9 >35 34.4 7.7, 154.7 94.5 21.9, 408.7 420.6 92.4, 1,914 Heavy smoker: smoker of 1 pack per day. Light smoker: nonsmoker or smoker of <1 pack per day for age, study area, raw fruit and vegetable consumption, and locality. Table 3. Joint odds s for annual income and frequency of raw fruit and vegetable consumption among Local Pashtoon in Quetta and Afghan with squamous cell esophageal cancer, 2001 2010 Consumption of raw Annual income fruits and vegetables Rs.25,000/- Rs. 10,000-Rs.24,999/- <Rs.10,000/- (no. of servings per week) >18.3 1.0 3.9 1.4, 11.0 7.8 2.6, 23.4 11.7-18.3 3.4 1.3, 9.2 4.5 1.6, 12.2 14.9 5.1, 43.2 7.1-11.6 1.8 0.6, 5.3 5.0 1.8, 13.5 15.9 5.7, 44.1 <7.1 2.5 0.9, 7.1 7.2 2.7, 19.2 17.0 6.3, 46.3 for age, study area, years of naswar, naswar taking, number of Hot Tea per week, and locality. DISCUSSION In this study, we found elevated risks of esophageal cancer in both Afghans and Local Pashtoon in Quetta in relation to various indicators of low social class, especially low annual income; the social class associations contributed to the higher Frequency among Afghans than among Local Pashtoon in Quetta and appeared to be independent of other risk factors. we noted that moderate/heavy use of Hot Tea, tobacco naswar taking, and infrequent consumption of raw fruits and vegetables were major risk factors in both Afghan men and Local Pashtoon in Quetta Individuals who smoke and drink hot tea are considered at high risk of esophageal squamous cell carcinoma The combination of tobacco and moderate/heavy Hot Tea use was responsible for 92 percent of the tumors in both Local Pashtoon in Quetta and Afghan and for 92% of the excess Frequency among Afghans. Considen of all four risk factors, including diet and social class, accounted for virtually all of the disease, including the Afghan/Local Pashtoon in Quetta differential in frequency. Since it was not known which sociodemographic measures were most strongly related to risk of esophageal cancer, we examined a large number of variables, including education, income (annual income and poverty index), occupation (usual occupational group and occupation-based socioeconomic status), marital status, place of birth, and frequency of dental visits. Income was the social class variable most strongly associated with risk. In agreement with previous studies 14-16, we found significantly elevated risks for the lowest level of annual income versus the highest 4.3 for Local Pashtoon in Quetta and 8.0 for Afghans, after adjustment for the potentially confounding factors Hot Tea use, Naswar taking, and diet). In addition to their higher risks, Afghan men had a greater frequency of controls with incomes less than Rs. 25,000/-, resulting in a HAR for low income that was 80 percent higher among Afghan men. A comparison of the distribution of annual family income reported by our hospital controls with that from 1991 Quetta. Data for the relevant locality groups, age groups, and geographic areas revealed that the percentages of low income (i.e., <RS10,000/-) subjects from each source were similar (Afghans=9%, study=8%; Local Pashtoon in Quetta: census=25%, study=28%). Consistent with other studies, we found elevated risks of squamous cell esophageal cancer for single men compared with married men 16,17,18,19, an inverse P J M H S VOL.6 NO.1 JAN MAR 2012 227

Frequency of Squamous Cell Esophageal Cancer among Afghan Men and local Pashtoons association with level of education 20,21,22,23,24, a greater risk for low status occupations compared with high status occupations (whether measured by job titles or educational requirements) 20,21,25, and an increased risk associated with incomes at or below the poverty level 26. In our study, adjustment for annual income reduced the magnitude and significance of the risks associated with other indicators of social class. In addition, our study showed slight and nonsignificant excess risks for both Afghans and Local Pashtoon in Quetta associated with being born in the Southern Afghanistan compared with other regions of the Afghanistan. Overall, the percentage of case men born in the Southern Afghanistan was more than three times greater among Afghans than among Local Pashtoon in Quetta. The findings are consistent with data indicating that Southern Afghanistanern-born Afghans are more disadvantaged economically than those born elsewhere 5. We also found elevated risks for subjects who reported visiting a dentist only rarely. This could reflect poor access to medical care due to poverty, oral infections, or social factors, such as purchases of Hot Tea and tobacco that took priority over dental care. Although social class has been linked to squamous cell esophageal cancer in a number of studies 15,19,20,21,22,24,25,26-,29, the underlying exposures or characteristics responsible for the association are unclear. Low social class is a surrogate for a set of lifestyle and other environmental factors including poor housing, unemployment or workplace hazards, limited access to medical care, stress, poor nutrition, and exposure to infectious agents (14). Some of these factors, such as nutritional status, may affect susceptibility to environmental carcinogens, but the mechanisms need to be clarified 29,30. The weakness of our study include the use of Hospital-based cases and controls; and the strengths are having large enough numbers of cases of each locality to estimate risks for Afghans and Local Pashtoon in Quetta separately; the relatively high participation rate, considering the poor survival rates for esophageal cancer; the use of direct interviews; and the ability to conduct cell type-specific analyses. Limitations include possible biases resulting from the tendency to interview cases with better survival; the potential for heightened recall among cases versus controls; the exclusion of subjects with missing data from the HAR analysis; and the problem of multiple comparisons and the possible influence of chance. The higher Frequency rates observed among Afghans for exposure to the same risk factors as Local Pashtoon in Quetta may reflect a susceptibility state conditioned by genetic traits or by nutritional, viral, or other factors associated with low social class. intake of moderate/heavy levels of Hot Tea, use of tobacco, infrequent consumption of raw fruits and vegetables, and low income were found to account for over 98% of the squamous cell esophageal cancer in this Hospital and for 99% of the excess Frequency among Afghans, It is clear that lifestyle modifications, including a reduction in Hot Tea and tobacco use and improvements in diet and living conditions, would markedly lower the Frequency of squamous cell esophageal cancer in groups. From a public health standpoint, our study suggests that the greatest impact would come from decreasing the levels of Hot Tea beverage consumption, especially among the 13 percent of the population who are the heaviest hot tea drinkers. 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